#include<stdio.h>
void main(){
    double a,b;

	printf(":\n",a);

	scanf("%lf",&a);

	if(a<=5000)
	{

    printf("˰:%lf\n",a);

	}

	else

{
	b=a-(a-5000)*0.05;

    printf("˰:%.6lf\n",b);

	}

}